The front action screw hole will need to be plugged and the new one will need to be milled. The recoil lug inlet needs to be moved forward as well as the ejection port. If it's already an ADL the bottom metal inlet is the same, but the mag box will need to be opened up. If not, the bottom metal inlet needs to be inletted as well.
As for labort rate.... It all depends on the guy doing it. Should take a skilled guy less than an hour. $65 and up should be close.